{"id":259324,"date":"2024-09-11T12:30:02","date_gmt":"2024-09-11T12:30:02","guid":{"rendered":"https:\/\/michigandigitalnews.com\/index.php\/2024\/09\/11\/fish-size-themselves-up-in-a-mirror-to-decide-if-they-can-win-a-fight\/"},"modified":"2025-06-25T17:11:23","modified_gmt":"2025-06-25T17:11:23","slug":"fish-size-themselves-up-in-a-mirror-to-decide-if-they-can-win-a-fight","status":"publish","type":"post","link":"https:\/\/michigandigitalnews.com\/index.php\/2024\/09\/11\/fish-size-themselves-up-in-a-mirror-to-decide-if-they-can-win-a-fight\/","title":{"rendered":"Fish size themselves up in a mirror to decide if they can win a fight"},"content":{"rendered":"<p> [ad_1]<br \/>\n<\/p>\n<div id=\"\">\n<figure class=\"ArticleImage\">\n<div class=\"Image__Wrapper\"><img fetchpriority=\"high\" decoding=\"async\" class=\"Image\" width=\"1349\" height=\"900\" alt=\"\" src=\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg\" sizes=\"(min-width: 1288px) 837px, (min-width: 1024px) calc(57.5vw + 55px), (min-width: 415px) calc(100vw - 40px), calc(70vw + 74px)\" srcset=\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=300 300w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=400 400w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=500 500w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=600 600w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=700 700w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=800 800w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=837 837w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=900 900w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=1003 1003w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=1100 1100w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=1200 1200w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=1300 1300w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=1400 1400w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=1500 1500w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=1600 1600w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=1674 1674w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=1700 1700w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=1800 1800w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=1900 1900w, https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/09\/10203456\/SEI_220931341.jpg?width=2006 2006w\" loading=\"eager\" fetchpriority=\"high\" data-image-context=\"Article\" data-image-id=\"2447427\" data-caption=\"A bluestreak cleaner wrasse checking itself out in the mirror\" data-credit=\"Osaka Metropolitan University\"\/><\/div><figcaption class=\"ArticleImageCaption\">\n<div class=\"ArticleImageCaption__CaptionWrapper\">\n<p class=\"ArticleImageCaption__Title\">A bluestreak cleaner wrasse checking itself out in the mirror<\/p>\n<p class=\"ArticleImageCaption__Credit\">Osaka Metropolitan University<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n<p>Before deciding whether or not to fight another fish, cleaner wrasse check their own reflection in a mirror and size themselves up.<\/p>\n<p>Bluestreak <a href=\"https:\/\/www.newscientist.com\/article\/2292064-female-cleaner-fish-can-judge-when-to-cheat-without-getting-caught\/\">cleaner wrasse<\/a> (<em>Labroides dimidiatus<\/em>) are remarkably bright. These finger-sized coral reef fish were the <a href=\"https:\/\/www.newscientist.com\/article\/2178329-a-species-of-fish-has-passed-the-mirror-test-for-the-first-time\/\">first fish to pass the mirror test<\/a>, a common assessment to see whether an animal recognises that the reflection is of its own body and not another animal. Researchers have now found that these wrasses use their likeness to construct a mental image of their body size, which they can compare to others.<\/p>\n<p>\n    <iframe title=\"This fish sizes it itself up in a mirror before it decides to fight\" width=\"1200\" height=\"675\" src=\"https:\/\/www.youtube.com\/embed\/1sNH0EgfrSA?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><br \/>\n    <\/iframe>\n<\/p>\n<p>First, <a href=\"https:\/\/www.researchgate.net\/profile\/Taiga-Kobayashi\">Taiga Kobayashi<\/a> at Osaka Metropolitan University in Japan and his colleagues tested the fish\u2019s willingness to go on the attack. Against the glass wall of the fish tank, they held up an image of another wrasse that was either 10 per cent larger or smaller than the real <a href=\"https:\/\/www.newscientist.com\/article\/2447128-watch-eels-escape-from-the-stomachs-of-fish-after-being-swallowed\/\">fish<\/a>. Regardless of the size of the model fish in the photograph, the territorial wrasses picked a fight.<\/p>\n<p>Then, they repeated the test but added a mirror, and the fish checked out their reflection. But when the researchers held up a photo of a larger or smaller cleaner wrasse to the glass pane, the fish chose to fight only smaller rivals.<\/p>\n<p>\u201cThis was unexpected because we had an image that this fish always shows aggression against rivals, regardless of size,\u201d says Kobayashi.<\/p>\n<p><span class=\"js-content-prompt-opportunity\"\/><\/p>\n<p>The tank was partitioned so that the wrasse couldn\u2019t see its reflection and the rival fish\u2019s photo at the same time \u2013 so scientists think the fish must be comparing the image to a mental approximation of their own body size.<\/p>\n<p>Cleaner wrasse evolved in an environment without mirrors, so how did they end up with this skill? Whether in the lab or in the wild, it benefits a fish to know what size they are before picking a fight, says Kobayashi. In other words, the fish were clever enough to employ the mirror as a <a href=\"https:\/\/www.newscientist.com\/article\/mg24532690-700-your-decision-making-ability-is-a-superpower-physics-cant-explain\/\">decision-making<\/a> tool.<\/p>\n<section class=\"ArticleTopics\">\n<p class=\"ArticleTopics__Heading\">Topics:<\/p>\n<\/section><\/div>\n<p>[ad_2]<br \/>\n<br \/><a href=\"https:\/\/www.newscientist.com\/article\/2447414-fish-size-themselves-up-in-a-mirror-to-decide-if-they-can-win-a-fight\/?utm_campaign=RSS%7CNSNS&#038;utm_source=NSNS&#038;utm_medium=RSS&#038;utm_content=home\">Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>[ad_1] A bluestreak cleaner wrasse checking itself out in the mirror Osaka Metropolitan University Before deciding whether or not to fight another fish, cleaner wrasse<\/p>\n","protected":false},"author":1,"featured_media":259325,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[177],"tags":[],"_links":{"self":[{"href":"https:\/\/michigandigitalnews.com\/index.php\/wp-json\/wp\/v2\/posts\/259324"}],"collection":[{"href":"https:\/\/michigandigitalnews.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/michigandigitalnews.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/michigandigitalnews.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/michigandigitalnews.com\/index.php\/wp-json\/wp\/v2\/comments?post=259324"}],"version-history":[{"count":0,"href":"https:\/\/michigandigitalnews.com\/index.php\/wp-json\/wp\/v2\/posts\/259324\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/michigandigitalnews.com\/index.php\/wp-json\/wp\/v2\/media\/259325"}],"wp:attachment":[{"href":"https:\/\/michigandigitalnews.com\/index.php\/wp-json\/wp\/v2\/media?parent=259324"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/michigandigitalnews.com\/index.php\/wp-json\/wp\/v2\/categories?post=259324"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/michigandigitalnews.com\/index.php\/wp-json\/wp\/v2\/tags?post=259324"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}